1. Field of the Invention
The present invention relates to an automated molding machine for ultra small draft angle slurry molding products and, more particularly, to the automated molding machine for ultra small draft angle slurry molding products that descends an extrusion die to one stroke to match and mold with a slurry suction die, to achieve the effect of molding the slurry suction die with the extrusion die precisely at a designated position.
2. Description of the Related Art
At early stages, most industrial and household products were made of plastic. Later studies show that plastic products may release toxins to cause severe pollution to the environment, and it is difficult to recycle, reuse or decompose plastic products, thus resulting in a high recycling cost. Unfortunately, there is a huge amount of plastic products which has seriously damaged our environmental protection for years. In today's high level of environmental consciousness, developing non-toxic and recyclable materials becomes a mainstream of research and practical applications.
At present, a mixture of slurry and/or plant fiber is developed. A slurry suction die of a slurry molding product molding machine is used for slurry suction, then pressed and molded with an extrusion die, and finally hot-pressed to produce the product. This product is generally called a “molding product” or a “paper-plastic product” in order to have a clear distinction from the term and definition of a “plastic product”. The molding products made of the mixed material of slurry and/or plant fiber can be recycled and reused easily, so that they comply with the energy saving, carbon reduction, and environmental protection requirements. The molding products have become increasingly more important and popular in industrial, commercial and public areas.
The manufacture of molding products requires “slurry suction molding” and “hot press truing” processes, so that the conventional molding machine for manufacturing the molding products is equipped with devices for performing both slurry suction molding process and hot press truing process. The device used for the slurry suction molding process includes a main frame, a slurry box disposed at the bottom of the main frame, an up-and-down movable frame, and a slurry suction die disposed on the frame. The slurry suction die faces downwardly and remains at an initial position when the operation of the slurry suction molding device stops, and descends outwardly from the frame by external power when the operation of the slurry suction molding device starts. The slurry suction die is linked to descend one stroke and enter into the slurry box for performing a vacuum suction of the slurry through a plurality of slurry suction holes on the surface of the slurry suction die by using an external vacuum device to form a full slurry layer on a surface of the slurry suction die. Then, the frame is ascended to link and drive the slurry suction die together with the slurry layer to separate from the slurry box and ascend back to its original position. In the process, the slurry layer will gradually lower its humidity when the vacuum suction continues. While the frame is ascending, a turning mechanism installed on the frame drives the frame (together with the slurry suction die and the slurry layer) to be overturned. The slurry suction die and the slurry layer face upwardly and continue to move upwardly for one stroke and close with an extrusion die disposed at the top inside the main frame, so that the slurry layer is extruded (compressed) and molded into a blank. Since there is a space between the slurry suction die and the extrusion die, since the space is the profile of the expected molding product, and after the slurry suction die and the extrusion die jointly extrude (compress) the slurry layer, the molded blank becomes a blank similar to the expected molding product, but the blank is an intermediate product with a relatively high humidity. Then, the frame (together with the slurry suction die and the attached blank) is driven to descend, so that the slurry suction die and the blank are separated from the extrusion die, to complete the “slurry suction molding” process.
Now, it is necessary to perform the “hot press truing” process before the blank becomes the final molding product. A side frame is mounted on a side of the main frame, and a moving device has a hot-press lower mold (which is the moving mold) equipped with another vacuum device. The hot-press lower mold (which is the moving mold) of the moving device is moved a position exactly below the slurry suction die and the blank. The frame drives the slurry suction die and the blank to descend, and the blank is put into the hot-press lower mold (which is the moving mold). Then, the vacuum of the slurry suction die stops, and an air-blowing operation is performed. In the meantime, the suction of the hot-press lower mold (which is the moving mold) starts to suck the blank, and the frame drives the slurry suction die to ascend to its original position (Now, the blank has been transferred onto the moving mold). While the hot-press lower mold (which is the moving mold) is moved to a position exactly below a hot-press upper mold disposed at the top inside the side frame, the hot-press upper mold is driven by another external power to descend and close with the hot-press lower mold (which is the moving mold), and the heater is turned on to heat the blank and perform the hot press truing process. In the meantime, the vacuum suction force of the hot-press lower mold is maintained to facilitate extracting and sucking the steam quickly, to achieve a quick drying effect of the blank. This process not just dries the blank completely, but also shapes the blank. After the hot press truing process is completed, the original blank is converted into the molding product. Then, the heating of the hot-press upper mold is stopped, and the hot-press upper mold is ascended to its original position. In the meantime, the moving mold attaches and carries the molding product to move towards the outside of the side frame, and the molding product is collected.
The conventional molding machine used for manufacturing the molding product has a major shortcoming that it is difficult to control the turnover action of the turning mechanism. During the operation, a failure or an overturn may occur. In addition, the up-and-down movements of the frame are driven by external power (which is generally from a power cylinder), and there is no other mechanism for righting or aligning in the stroke. Thus, when the ascending or descending action reaches a fixed point, a deviation or a failure of aligning parallelly to the slurry suction die board may occur. When the slurry suction die is driven to ascend and close with the extrusion die or driven to descend to close with the moving mold, an unmatched mold closing occurs frequently. Therefore, a shutdown is required for making adjustments and corrections. The frequent occurrence of unmatched mold closing results in a low yield rate, wastes manufacturing time and labor, and incurs a very high manufacturing cost.
In another conventional molding machine for manufacturing molding products, the extrusion die is placed at a fixed position on the top inside the main frame. The slurry suction die is moved upwardly for one stroke and engaged with the extrusion die to extrude (compress) the slurry layer to shape a blank. Thus, if the slurry suction die moves one stroke calculated by using the initial position as the initial point, it is necessary to calculate the stroke of moving downwardly into the slurry box and then moving upwardly back to its original position as well as calculating the stroke of moving upwardly to close mold with the extrusion die and then moving downwardly to its original position. In other words, for the conventional slurry suction die for each time of molding a blank, it is necessary to have a stroke of moving downwardly→upwardly→upwardly→downwardly, and thus wasting the manufacturing time and incurring a high manufacturing cost. Obviously, the conventional molding machines require further improvements.